HttpClient4.3使用总结

1.Get

publicstaticStringgetResultWithGet(HttpServletRequestrequest,Stringurl)throwsException{
Stringresult=null;
HttpClientclient=getClient();
try{
HttpGetget=newHttpGet(url);
HttpResponseresponse=client.execute(get);
result=getResponseBodyAsString(response);
}finally{
client.getConnectionManager().shutdown();
}
returnresult;
}

2、Post

publicstaticStringgetResultWithPost(HttpServletRequestrequest,Stringurl)throwsException{
Stringjson=null;
HttpClientclient=getClient();
try{
HttpPostpost=newHttpPost(url);
@SuppressWarnings("unchecked")
Map<String,String[]>map=request.getParameterMap();
Set<String>keySet=map.keySet();
JSONObjectjo=newJSONObject();
for(Strings:keySet){
if(!"".equals(map.get(s)[0])){
jo.element(s,map.get(s)[0]);
}

}
StringEntityreqEntity=newStringEntity(jo.toString(),"UTF-8");
reqEntity.setContentType("application/json");
post.setEntity(reqEntity);
HttpResponseresponse=client.execute(post);
json=getResponseBodyAsString(response);
}finally{
client.getConnectionManager().shutdown();
}
returnjson;
}

3、Put

publicstaticStringgetResultWithPut(HttpServletRequestrequest,Stringurl)throwsException{
Stringjson=null;
HttpClientclient=getClient();
try{
HttpPutput=newHttpPut（url);
@SuppressWarnings("unchecked")
Map<String,String[]>map=request.getParameterMap();
Set<String>keySet=map.keySet();
JSONObjectjo=newJSONObject();
for(Strings:keySet){
if(!"".equals(map.get(s)[0])){
jo.element(s,map.get(s)[0]);
}

}
StringEntityreqEntity=newStringEntity(jo.toString(),"UTF-8");
reqEntity.setContentType("application/json");
put.setEntity(reqEntity);
HttpResponseresponse=client.execute(put);
json=getResponseBodyAsString(response);
}finally{
client.getConnectionManager().shutdown();
}
returnjson;
}

4、Delete

publicstaticStringgetResultWithDelete(HttpServletRequestrequest,Stringurl)throwsException{
Stringresult=null;
HttpClientclient=getClient();
try{
HttpDeletedelete=newHttpDelete(url);
HttpResponseresponse=client.execute(delete);
result=getResponseBodyAsString(response);
}finally{
client.getConnectionManager().shutdown();
}
returnresult;
}

5、getResponseBodyAsString

publicstaticStringgetResponseBodyAsString(HttpResponseresponse)throwsException{
StringBuildersb=newStringBuilder();
HttpEntityhttpEntity=response.getEntity();
if(httpEntity!=null){
httpEntity=newBufferedHttpEntity(httpEntity);
InputStreamis=httpEntity.getContent();
BufferedReaderbr=newBufferedReader(newInputStreamReader(is,"UTF-8"));
Stringstr;
while((str=br.readLine())!=null){
sb.append(str);
}
is.close();
}
returnsb.toString();
}

6、文件上传

publicStringuploadAttachment(HttpServletRequestrequest){
Stringjson=null;
HttpClientclient=TicketUtils.getClient();
try{

HttpPostpost=newHttpPost(url);

DiskFileItemFactoryfac=newDiskFileItemFactory();
ServletFileUploadupload=newServletFileUpload(fac);
upload.setHeaderEncoding("UTF-8");
@SuppressWarnings("unchecked")
List<FileItem>fileList=upload.parseRequest(request);
Iterator<FileItem>it=fileList.iterator();
List<File>tempFileList=newArrayList<File>();
while(it.hasNext()){
FileItemitem=it.next();
if(!item.isFormField()){
StringfileName=item.getName();
if(fileName!=null)
{
Filefile=newFile(fileName);
item.write(file);
MultipartEntitymultipartEntity=newMultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE,null,Charset.forName("UTF-8"));
FileBodyfileBody=newFileBody(file);
multipartEntity.addPart(fileName,fileBody);
post.setEntity(multipartEntity);
tempFileList.add(file);
}
}
}
HttpResponseresponse=client.execute(post);
json=TicketUtils.getResponseBodyAsString(response);
//deletetempfiles
for(Filefile:tempFileList){
file.delete();
}
}catch(Exceptione){
log.error(e);
json=JsonUtil.getJsonString(Const.ERROR_MESSAGE,EM.TICKET_EXCEPTION);
}finally{
client.getConnectionManager().shutdown();
}
returnjson;
}

7、文件下载

publicvoiddownloadAttachment(HttpServletRequestrequest,HttpServletResponseresponse,@PathVariable("fileId")IntegerfileId){
HttpClientclient=TicketUtils.getClient();
try{
HttpGetget=newHttpGet(urlStr);

ResponseHandler<byte[]>handler=newResponseHandler<byte[]>(){
publicbyte[]handleResponse(HttpResponseresponse)
throwsClientProtocolException,IOException{
HttpEntityentity=response.getEntity();
if(entity!=null){
returnEntityUtils.toByteArray(entity);
}else{
returnnull;
}
}
};
byte[]charts=client.execute(get,handler);

URLurl=newURL(urlStr);
HttpURLConnectionuc=(HttpURLConnection)url.openConnection();
response.reset();
response.addHeader("Content-disposition",uc.getHeaderField("Content-disposition"));
OutputStreamoutput=newBufferedOutputStream(response.getOutputStream());
output.write(charts);
output.flush();
output.close();
get.releaseConnection();
}catch(Exceptione){
log.error(e);
}finally{
client.getConnectionManager().shutdown();
}
}